g-C3N4/AgBr nanocomposite decorated with carbon dots as a highly efficient visible-light-driven photocatalyst.

Visible-light-driven photocatalysis as a green technology has attracted intense interest due to its potential applications in environmental remediation. However, the poor visible light utilization and low electron-hole separation efficiency of photocatalysts largely limited their practical application. In this work, a new ternary visible-light driven photocatalyst of g-C 3 N 4 /CDs/AgBr has been prepared by the introduction of carbon dots (CDs) onto the surface of g-C 3 N 4 , followed by in-situ growth of AgBr nanoparticles on CDs-modified g-C 3 N 4 nanosheets. The g-C 3 N 4 /CDs/AgBr nanocomposite exhibits excellent photocatalytic efficiency for organic pollutant degradation, which is about 4.0, 5.3 and 2.3 times higher than that of AgBr, g-C 3 N 4 and g-C 3 N 4 /AgBr, respectively. The result indicates the introduction of CDs into g-C 3 N 4 /AgBr can largely improve the photocatalytic activity since CDs act as the light absorber and the electron mediator between g-C 3 N 4 and AgBr, which effectively promote the separation of photogenerated charge carriers and the utilization of visible light. Moreover, the photocatalytic activity of g-C 3 N 4 /CDs/AgBr has no obvious decrease after four photodegradation cycles, demonstrating a high photocatalytic stability. This study highlights the potential application of highly efficient CDs decorated photocatalysts in waste water purification. [ABSTRACT FROM AUTHOR]